TiB₂ Wettable Cathode by Suspension Plasma Spray

Aluminium permeates our daily lives, from cans to airplanes. However, important improvements are still needed to the aluminium production process, especially the performance of aluminium electrolysis. Indeed, this process produces significant greenhouse gas emissions and is highly energy-consuming. To answer these issues, inert anodes and wettable cathodes are among innovative ideas which are thoroughly under research to improve the process efficiency and reduce environmental impact. As for wettable cathodes, one of the best options considered so far is a titanium diboride coated cathode. In this work, an axial-injection plasma spray torch was used to deposit titanium diboride coatings on graphite substrates by suspension plasma spray. Parametric studies were carried out in order to optimize the coatings’ microstructure for the desired application and to properly melt the particles. A gas shroud was used in order to reduce the oxidation of in-flight particles which, according to the literature, is a key issue when depositing this material.